Documentation

Telegraf

  • Telegraf v1.8.0+
Plugin source Download configuration

Strings Processor Plugin

This plugin allows to manipulate strings in the measurement name, tag and field values using different functions.

Introduced in: Telegraf v1.8.0 Tags: transformation OS support: all

Global configuration options

Plugins support additional global and plugin configuration settings for tasks such as modifying metrics, tags, and fields, creating aliases, and configuring plugin ordering. See CONFIGURATION.md for more details.

Configuration

# Perform string processing on tags, fields, and measurements
[[processors.strings]]
  ## Convert a field value to lowercase and store in a new field
  # [[processors.strings.lowercase]]
  #   field = "uri_stem"
  #   dest = "uri_stem_normalised"

  ## Convert a tag value to uppercase
  # [[processors.strings.uppercase]]
  #   tag = "method"

  ## Convert a field value to titlecase
  # [[processors.strings.titlecase]]
  #   field = "status"

  ## Trim leading and trailing whitespace using the default cutset
  # [[processors.strings.trim]]
  #   field = "message"

  ## Trim leading characters in cutset
  # [[processors.strings.trim_left]]
  #   field = "message"
  #   cutset = "\t"

  ## Trim trailing characters in cutset
  # [[processors.strings.trim_right]]
  #   field = "message"
  #   cutset = "\r\n"

  ## Trim the given prefix from the field
  # [[processors.strings.trim_prefix]]
  #   field = "my_value"
  #   prefix = "my_"

  ## Trim the given suffix from the field
  # [[processors.strings.trim_suffix]]
  #   field = "read_count"
  #   suffix = "_count"

  ## Replace all non-overlapping instances of old with new
  # [[processors.strings.replace]]
  #   measurement = "*"
  #   old = ":"
  #   new = "_"

  ## Trims strings based on width
  # [[processors.strings.left]]
  #   field = "message"
  #   width = 10

  ## Decode a base64 encoded utf-8 string
  # [[processors.strings.base64decode]]
  #   field = "message"

  ## Sanitize a string to ensure it is a valid utf-8 string
  ## Each run of invalid UTF-8 byte sequences is replaced by the replacement string, which may be empty
  # [[processors.strings.valid_utf8]]
  #   field = "message"
  #   replacement = ""

Values can be modified using the listed function in-place or stored in another field or tag.

The operations are executed in the configuration order.

Specify the measurement, tag, tag_key, field, or field_key you want to processed in each section and optionally a dest if you want the result stored in a new tag or field. You can specify lots of transformations on data with a single strings processor.

If you’d like to apply the change to every tag, tag_key, field, field_key, or measurement, use the value "*" for each respective field.

The dest setting will be ignored if "*" is used.

Trim, TrimLeft, TrimRight

The trim, trim_left, and trim_right functions take an optional parameter: cutset. This value is a string containing the characters to remove from the value.

TrimPrefix, TrimSuffix

The trim_prefix and trim_suffix functions remote the given prefix or suffix respectively from the string.

Replace

The replace function does a substring replacement across the entire string to allow for different conventions between various input and output plugins. Some example usages are eliminating disallowed characters in field names or replacing separators between different separators. Can also be used to eliminate unneeded chars that were in metrics. If the entire name would be deleted, it will refuse to perform the operation and keep the old name.

Example

A sample configuration:

[[processors.strings]]
  [[processors.strings.lowercase]]
    tag = "uri_stem"

  [[processors.strings.trim_prefix]]
    tag = "uri_stem"
    prefix = "/api/"

  [[processors.strings.uppercase]]
    field = "cs-host"
    dest = "cs-host_normalised"

Sample input:

iis_log,method=get,uri_stem=/API/HealthCheck cs-host="MIXEDCASE_host",http_version=1.1 1519652321000000000

Sample output:

iis_log,method=get,uri_stem=healthcheck cs-host="MIXEDCASE_host",http_version=1.1,cs-host_normalised="MIXEDCASE_HOST" 1519652321000000000

Second Example

A sample configuration:

[[processors.strings]]
  [[processors.strings.lowercase]]
    tag_key = "URI-Stem"

  [[processors.strings.replace]]
    tag_key = "uri-stem"
    old = "-"
    new = "_"

Sample input:

iis_log,URI-Stem=/API/HealthCheck http_version=1.1 1519652321000000000

Sample output:

iis_log,uri_stem=/API/HealthCheck http_version=1.1 1519652321000000000

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